The Politics of Intelligence · Episode 6 of 9 · 49 min
The Fabricated Twin Study Behind the Race-and-IQ Claim: Cyril Burt
A central pillar of the race-and-IQ case, the claim that IQ is about 80 percent heritable, rested heavily on the separated-twin studies of Sir Cyril Burt. After his death, Leon Kamin noticed impossible consistency in the numbers and Oliver Gillie reported in 1976 that Burt's collaborators could not be found. The fraud verdict has been challenged, but the evidence behind the heritability claim was badly damaged.
Who's who
- Cyril Burt+2 more episodesBritish psychologist whose separated-twin data underpinned hereditarian claims
- Leon Kamin+2 more episodesPrinceton psychologist who found impossible invariance in Burt's correlations
- Oliver GillieSunday Times medical correspondent who broke the 1976 exposé
- Arthur Jensen+7 more episodesBerkeley psychologist who leaned heavily on Burt's data
- L. S. HearnshawHistorian of psychology who concluded Burt fabricated twin scores
- Robert B. JoynsonPsychologist who challenged the fraud verdict in The Burt Affair
- Ronald FletcherSociologist who independently defended Burt
- William Shockley+3 more episodesNobel physicist who used the hereditarian argument
Where it happens
- London, England+7 more episodesBurt's birthplace and base as an educational psychologist
- University College London, EnglandWhere Burt held the psychology chair from 1931
Timeline
- 1943Burt publishes first separated-twin paper, correlation 0.770
- 1966Third twin paper reports about fifty-three pairs, same correlation
- 1974Kamin publishes The Science and Politics of I.Q.
- October 24, 1976Gillie's Sunday Times article says crucial data was faked
- 1979Hearnshaw's biography concludes the twin scores were fabricated
- 1989Joynson's The Burt Affair challenges the fraud verdict
Still debated
Whether Burt committed outright fraud is not fully settled, since Joynson and Fletcher raised methodological objections. Even if Burt were cleared, that would not close the logical gap between within-group heritability and the causes of a group difference.
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